1. Field of the Invention
The present invention relates to locking quick connect assemblies for removably coupling a first tube and a second tube and more particularly to automotive style locking quick connect assemblies which may include a redundant lock.
2. Description of the Prior Art
Locking quick connect assemblies are well known in the art for removably coupling a first tube and a second tube. Locking quick connect assemblies are widely utilized in the automotive industry to removably couple the fluid lines of an automobile such as the fuel lines, brake lines, oil lines, water lines, hydraulic lines, air lines, and the like. Automobiles are typically assembled on moving assembly lines where subassemblies are installed at various locations along the line. Accordingly, locking quick connect assemblies are advantageous because they allow assembly line workers to quickly and easily connect fluid lines leading to and away from the various subassemblies as the automobile travels along the assembly line. Additionally, since locking quick connect assemblies may be decoupled at a later time, service and repair of the automobile can be accomplished more easily because components are more readily removed and replaced.
The locking quick connect assemblies known in the art, such as the one disclosed in U.S. Pat. No. 5,542,716 to Szabo et al., entitled “Quick Connector with Snap-on Retainer,” generally include a quick connect housing having a male retention segment for engagement with the first tube and a female segment for receiving the second tube. It should be appreciated that in the automotive industry, the second tube is often referred to as an SAE pin and includes a bead extending annularly about the second tube. The male retention segment of the quick connect housing typically has a tubular shape for engagement with the first tube. The male retention segment may further present a plurality of annular barbs including several retention barbs being axially spaced and ramped up to a greater radial diameter to facilitate insertion of the male retention segment into the first tube and to resist subsequent separation between the first tube and the male retention segment. The female segment of the quick connect housing typically extends axially away from the male retention segment and has an interior surface defining a central bore for receiving the second tube. The interior surface of the female segment may include stepped portions for engaging the bead of the second tube and for receiving seals that engage the interior surface of the female segment and the second tube.
As is known in the art, a redundant lock mechanism may be desirable in certain applications to ensure that the locking quick connect assembly does not decouple unintentionally. The redundant lock mechanism typically takes the form of a clip that is inserted into an opening in the female segment of the quick connect housing. As it is inserted, the clip engages the bead of the second tube to prevent separation of the second tube and the quick connect housing. Often, this redundant lock mechanism or clip is a physically separate part that is not attached to the quick connect housing. Thus, several problems arise. The separate clip may be lost before installation occurs or when the locking quick connect assembly is decoupled during service or repair operations. The separate clip may also be difficult to insert into the opening in the quick connect housing in blind installation situations where the quick connect assembly may be felt but not seen. To address these problems, locking quick connect assemblies have been developed, such as the one disclosed in U.S. Pat. No. 5,649,724 to Wiethorn, entitled “Secondary Latch and Indicator for Fluid Coupling,” where the clip is attached to the quick connect housing by a hinge. These locking quick connect assemblies however still suffer from several problems. The hinged clip tends to break off either before installation occurs or when the locking quick connect assembly is decoupled during service or repair operations. Also, regardless of whether the clip is attached to the quick connect housing or is a separate part, such clips tend to be difficult to remove once installed and may even require tools for removal. This can be especially problematic in blind installation situations where use of tools is difficult or where there is little room to manipulate the locking quick connect assembly. What is needed is a locking quick connect assembly that is more durable, does not contain a loose clip component, and can be more easily decoupled.
The Applicant has appreciated that a twist lock mechanism would meet these needs. However, it was found that the twist lock mechanisms known in the art could not be easily adapted to this style of quick connect assembly. The twist lock mechanisms known in the art, such as the one disclosed in U.S. Pat. No. 7,566,079 to Callahan et al., entitled “Duct Coupling,” serve to removably couple a pair of ducts in an end-butting arrangement. However, the twist lock mechanism disclosed is not configured to receive a second tube, such as an SAE pin, and lock against the bead of the second tube to prevent separation between the second tube and the quick connect housing. Accordingly, known twist lock mechanisms do not function to lock in a single motion wherein the second tube is laterally advanced with respect to the quick connect housing. Moreover, prior art twist lock mechanisms can be prone to undesired decoupling where the twist lock mechanism experiences unwanted rotation to its unlocked position. Accordingly, what is needed is a clipless locking quick connect assembly that is durable, has a simple locking motion, unlocks easily and without tools, and which may include a redundant lock that prevents unwanted unlocking of the twist lock mechanism.